An optical layered body, which includes functional layers having various functions such as an antireflection property, a hardness property, an antistatic property, and an antiglare property, is provided on the outermost surfaces of image display devices such as a cathode-ray tube (CRT) display device, a liquid crystal display (LCD), a plasma display (PDP), an electroluminescence display (ELD), and a field emission display (FED) (Japanese Kokai Publication 2006-126808, Japanese Kokai Publication 2005-107005, and Japanese Kokai Publication 2004-69867).
As one of such functional layers, there has been known a low refractive index layer which may prevent reflection of external light and the like due to its refractive index different from that of other layers. As a method for forming such a low refractive index layer, there has been known a method for forming a layer by adding hollow silica.
On the other hand, a predetermined hardness is required in order to use an optical layered body as a product, and in order to evaluate a hardness property of the produced optical layered body, a pencil hardness test is generally carried out in conformity to JIS K 5600. However, in the case of the optical layered body which has a low refractive index layer containing the hollow silica, the hollow silica is crushed upon the pencil hardness test, which causes reduction in color reproducibility and deformation of the surface at the crushed portion, so that an appearance becomes poor. Thus, there has been a problem that the optical layered body after the test cannot be used as a product.
Therefore, a method for producing an optical layered body, which has a favorable appearance without deformation, has no influence on an optical property, and can be used as a product after the pencil test, has been required.